It’s becoming an annual reminder, but an important one so newcomers (etc.) don’t get worried: If you see reddish-orange water like this off West Seattle shores, it’s not a spill, and it’s not poisonous. It’s a bloom of single-cell plankton known as “noctiluca.” Thanks to Beach Drive resident Lura Ercolano for sharing the photo she took this morning, now that the current wave has hit full bloom; she helped educate us and readers about it two years ago, too. The state tracks blooms like this, so if you see it, you’ll find an e-mail address for reporting it on this Department of Ecology page, which explains that blooms usually result from “abundant sunlight, nutrients, and the right water conditions.”

FRIDAY FOLLOWUP: The state Ecology Department has a news release this morning about the bloom, earlier than usual, they say. You can see it here.